Housings with roller bearings are well known. Generally, there are two types of these assemblies. The fixed type contains a fixed position roller bearing assembly which is capable of handling only slight shaft misalignment. These units are usually compact, of relatively few parts, and require only a minimum of space. A second type is known as a "self-aligning" and permits greater shaft misalignment. Self-aligning units are usually more complex, larger, require a greater number of parts, and are generally more expensive.